If it is it able to walk around? Put weight on that foot? If you can't visibly see a mark, see if it will allow you to touch. Leave on the ground or place on a table, stand behind, talk gently, while moving your hand down the forearm to the paw. Most likely will not be happy. If you have help, all the better. Feel for dampness (blood). If none, place thumb over top of paw and gently rub forefinger across pad , then between each toe . Many cats get spurs or hitchhikers caught in their paws are unable to remove themselves. I have a tom-cat who insist on running after anyone or thing he thinks is a danger to me, and ends up catching a tree root or some such thing and damaging his dew claw. If your having a hard time trying this, get a real warm wet cloth ready, hold him/her tight and squeeze the water from the cloth over the paw. Do as often as you can, (when wet, he/she will try to clean) to ward off any possible infection until you can see a vet.
